SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1eaf9e5b80b1822d706c3828b9a6778445bd650a7bd1834fd85a2933bc388dd5' 
  AND token = '0Bl4WBC1Tya5P0MjywzCdS+qg/jADxhgNRGW4edefGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}